RESOURCE DIVIDING METHOD AND BUS CONNECTING MECHANISM IN BUS SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a resource dividing method and a bus connecting device which do not need a register for system resource allocation, are of simple hardware constitution and facilitates system extension. ;SOLUTION: When response signals are returned from plural I/O systems 8-12 with time lag at an access request made by a CPU 1, I/O buses 3 and 4 which are connected with bus connection devices 5 and 6 of the I/O system having quickly responded are validated and the I/O buses which are connected with the other bus connection devices are invalidated. When the response signals are returned at the same time, the bus connecting device of some I/O system outputs a data validation signal to a CPU bus 2 and other bus connecting devices outputs CPU interruption signals. The CPU detects inconsistency being generated in an I/O cycle by receiving a contrary signal and when the response signal is not returned from any I/O system, a timer 7 sends time-out signals to the respective bus connecting devices make all the I/O buses ineffective.;COPYRIGHT: (C)2000,JPO